Maintenance

Achieving the best screen-printing performance and productivity is greatly dependent on the selection of the correct LC squeegee for the application and proper Squeegees maintenance. When printing, monitor production time and rotate Squeegees frequently. (The necessary rotation frequency is dependent on the ink / solvent system involved in the application) By doing so, you will achieve a more uniform print quality and increase the life of your Squeegees. A Squeegee should always be wiped clean and dry following removal from the press and stored in a dry environment at room temperature. The blade should be allowed to recover from the ink and solvent attack and rest for a period of 24 hours. It can then be placed back into production, or if necessary re-sharpened and placed back into production.
          The Squeegees is supplied in coils, the Squeegees material has excellent elastic memory and will roll out into a 3500mm strip without retaining the curve of the roll. However it is recommended where there will be long-term storage (3 months or more) the Squeegee should be uncoiled and laid on a smooth surface free from raised lips or edges.
Both grades of material should be stored at a maximum temperature of +40℃ with a relative maximum humidity of 50%.
During operation it is important the Squeegee is clamped correctly, if the blade becomes unseated from the clamp of handle it may produce uneven coverage or cause large areas of the print to fail to flood with ink.
Good Squeegees management needs to be developed by the user to extend the useful life of the blade.
The most important factor to extend the life of the Squeegees blades is to allow it to 'rest', which permits evaporation of solvents, which have absorbed into the surface. The "resting" of the blade should take place in a warm and well-ventilated area and for as long as possible and not usually for less than 24 hours. To enable this be effective it is recommended the users have three to five blades pre-assembled into holders and available for use on a rotating basis.
There is no specific time scale between blade changes as each set of circumstances may alter depending on printing conditions. The user should find the optimum time by observing the blade in operation, when they see any sign of swelling the blade should be changed.
Two big reasons may make Squeegees " become invalid " ------ the excessive wear and dilapidation. Through selecting proper squeegee and maintaining properly, this can be avoided.

A: The cause of excessive wear is as follows:
1. Squeegees pressure is too heavy.
2. Effective height is not proper. Since the effective height is too short as a result of losing flexibility after squeegee is grinded repeatedly.
3. Improper Squeegees printing angle (too big or too small). Too big angle makes Squeegees produce hurried successive shake in printing so that excessive wear occurs. Too small angle makes the contact surface of squeegee and the stencil too big.
4. Overdue Squeegees. All the polymers for making Squeegees will lose a part of physical property because of a long time no matter used or not. If your storage of squeegee is overdue, you are suggested to throw it away.
5. Use unitary Squeegees for a long time. Proper use alternately.

B: Dilapidation is the splitting phenomenon of little pellet produced by Squeegees blade-edge to make printing produce anomalous stripe on image. The cause is as follows:

1. Squeegees is soaked in printing ink for a long time. All the printing ink may damage the properties of Squeegees; even the water-based printing ink can affect the stability of  Squeegees. Besides the alternate use of Squeegees, it must be cleaned in time after use of  Squeegees to remove all the extra printing ink thoroughly attached on Squeegee. The habit of putting the Squeegees into the solvent for washing should also be given up since the squeegee absorbs excessive solvent, the opportunity of dilapidation will be increased.
2. Overdue Squeegees. (see the A.4 above).
3. Improper Squeegees hardness. Generally speaking, the Squeegees with higher shore hardness can endure solvent fairly. If you find certain hardness of Squeegees can reach to ideal effect by experiment, you are suggested to choose the Squeegees with a little bit higher hardness, such as 5 degrees or 10 degrees.
4. Improper Squeegees. Perhaps the Squeegees polymer that you now use does not match with the printing ink, you are suggested to use the Squeegees of high quality series or UV series squeegee, which is made by special prescription and can bear strong aggressive solvent and UV ink.